// Package tray Windows 系统托盘实现（使用 win32 API）
package tray

import (
	"log"
	"sync"
	"unsafe"

	"golang.org/x/sys/windows"
)

// Hook 托盘图标句柄
var hook windows.Handle

// MenuHandle 菜单句柄
type MenuHandle uintptr

// Tray 系统托盘管理器
type Tray struct {
	mu       sync.Mutex
	visible  bool
	callback uintptr // WNDPROC 回调
	hWnd     windows.Handle
}

// MenuItem 菜单项
type MenuItem struct {
	ID   uint32
	Text string
}

// NewTray 创建系统托盘
func NewTray(iconData []byte, tooltip string) *Tray {
	t := &Tray{}
	if err := t.init(iconData, tooltip); err != nil {
		log.Printf("[tray] init failed: %v", err)
		return nil
	}
	return t
}

func (t *Tray) init(iconData []byte, tooltip string) error {
	// 获取当前进程窗口
	hWnd, _ := windows.GetForegroundWindow()
	if hWnd == 0 {
		return windows.ERROR_ACCESS_DENIED
	}
	t.hWnd = hWnd

	// 注册托盘图标
	// NOTIFYICONDATA structure
	// https://docs.microsoft.com/en-us/windows/win32/api/shellapi/ns-shellapi-notifyicondataa
	data := &notifyIconData{
		CbSize:      uint32(unsafe.Sizeof(notifyIconData{})),
		HWnd:        uint32(hWnd),
		UID:         1000,
		UFlags:      NIF_MESSAGE | NIF_ICON | NIF_TIP,
		UCallbackMessage: WM_USER + 1000,
		HIcon:       0, // 使用默认图标
	}

	// 设置 tooltip
	for i := 0; i < len(tooltip) && i < 128; i++ {
		data.Tip[i] = uint8(tooltip[i])
	}
	data.Tip[len(tooltip)] = 0

	// 添加托盘图标
	ret, _, _ := procShellNotifyIcon.Call(
		SHM_ADD,
		uintptr(unsafe.Pointer(data)),
	)
	if ret == 0 {
		return windows.GetLastError()
	}

	t.visible = true
	return nil
}

// Destroy 销毁托盘图标
func (t *Tray) Destroy() {
	t.mu.Lock()
	defer t.mu.Unlock()
	if !t.visible {
		return
	}
	data := &notifyIconData{
		CbSize: uint32(unsafe.Sizeof(notifyIconData{})),
		HWnd:   uint32(t.hWnd),
		UID:    1000,
		UFlags: NIF_MESSAGE,
	}
	procShellNotifyIcon.Call(SHM_DELETE, uintptr(unsafe.Pointer(data)))
	t.visible = false
}

// Show 显示托盘
func (t *Tray) Show(iconData []byte, tooltip string) error {
	t.mu.Lock()
	defer t.mu.Unlock()
	if t.visible {
		return nil
	}
	return t.init(iconData, tooltip)
}

// Hide 隐藏托盘
func (t *Tray) Hide() {
	t.mu.Lock()
	defer t.mu.Unlock()
	if !t.visible {
		return
	}
	data := &notifyIconData{
		CbSize: uint32(unsafe.Sizeof(notifyIconData{})),
		HWnd:   uint32(t.hWnd),
		UID:    1000,
		UFlags: NIF_MESSAGE,
	}
	procShellNotifyIcon.Call(SHM_DELETE, uintptr(unsafe.Pointer(data)))
	t.visible = false
}

// IsVisible 是否可见
func (t *Tray) IsVisible() bool {
	t.mu.Lock()
	defer t.mu.Unlock()
	return t.visible
}

// ─────────────────────────────────────────────
// Win32 API 定义
// ─────────────────────────────────────────────

const (
	WM_USER            = 0x0400
	SHM_ADD  uintptr   = 0x00000000
	SHM_DELETE uintptr   = 0x00000001

	NIF_MESSAGE = 0x00000001
	NIF_ICON    = 0x00000002
	NIF_TIP     = 0x00000004
)

// NOTIFYICONDATA struct
type notifyIconData struct {
	CbSize           uint32
	HWnd             uint32
	UID              uint32
	UFlags           uint32
	UCallbackMessage uint32
	HIcon            uintptr
	Tip              [128]uint8
}

var (
	procShellNotifyIcon = mustLoad("shell32.dll").MustFindProc("Shell_NotifyIconA")
)

func mustLoad(dllName string) *windows.DynLib {
	dll, err := windows.LoadDLL(dllName)
	if err != nil {
		log.Fatalf("[tray] failed to load %s: %v", dllName, err)
	}
	return dll
}